The present invention relates in general to reaction with distillation columns wherein mass transfer and chemical reaction occur within the same general region and, more particularly, to a structure within that region for containing solid catalyst particles which cause the chemical reaction to occur. The invention also relates to a reaction process employing a plurality of such structures.
Conventional catalytic reaction structures include containers which are filled with solid catalyst particles and are arrayed within a distillation column reactor. One example of a structure of this type, as disclosed in U.S. Pat. No. 4,307,254, comprises a cloth belt having a plurality of pockets which contain the catalyst particles and which are supported within the reactor by a steel wire support structure. The hydraulic characteristics of a reaction with distillation process which employs the cloth belt can be desirable because the liquid stream is free to flow through the open areas surrounding the cloth belt. The catalyst effectiveness or reactivity, however, may be inadequate in certain applications because the liquid is not forced to flow through the catalyst but instead merely diffuses through the catalyst after soaking through the cloth covering.
In other applications in which the cloth belt is used, the column region containing the cloth belt may be flooded with liquid to a preselected level in order to enhance the catalytic reaction of the liquid stream. Because the flooded conditions produce a large volume of backmixed liquid in that portion of the column, mass transfer between the liquid and vapor streams is substantially impeded. Provisions must then be made for allowing distillation to occur elsewhere within the column. The cloth belt in those applications thus functions primarily as a reaction structure and not a combination reaction with distillation structure.
Other types of catalytic distillation structures are disclosed in U.S. Pat. No. 5,057,468. The structures disclosed in that patent generally comprise cylindrical containers which hold catalyst and are provided with variously shaped openings for allowing passage of liquid and vapor through the containers. While the cylindrical containers can be more durable and easier to position than the cloth belt structures previous described, catalytic reaction still typically occurs primarily on the outer portions of the catalyst bed within each container because no mechanism is provided for forcing the liquid stream through the catalyst.